Reflector space satellite



Dec. 24, 1963 w. E. LANFORD 3,115,630:

1 REFLECTOR SPACE SATELLITE Filed Feb. 11, 1960 INVENTOR WADE E. LANFORDUnited States atent The invention described herein may be manufacturedand used by or for the Government of the United States of America forgovernmental purposes without the payment of any royalties thereon ortherefor.

The invention relates generally to a packaging arrangement, and moreparticularly to a method of compactly packaging a centrifugallyexpandable lightweight and flexible sheet of material, such for exampleas a space reflector.

The problem has existed from the very start of recent scientificinterest in space technology of how to deploy objects such as antennas,radar reflectors and the like into the earths upper atmosphere and theregions of outer space. Antennas and the like are highly important inthe electronic communications field since the electromagnetic waves ofradio, television and radar can be transmitted from one point of theearths surface to the antenna and then reflected, or bounced, back toanother point on the cart. s surface. By this method of tran mission therange of communication can be greatly increased. However, the limitedpayload capabilities of present day carrier vehicles have restrictedefforts to place satellites of this type in orbit about the earth.

Accordingly, one object of the present invention is to provide a novelspace reflector.

Another ob lect of this invention is to provide a new and improvedmethod of packaging a reflector space satellite.

A further object of the invention is to provide a new and improvedpackaged flexible electromagnetic wave reflector.

A still further obg'ect of the instant invention is to provide a novelcentrifugally expanded packaging configuration for a reflector spacesatellite.

One still further object of the invention is to provide a new andimproved packaged lightweig t space satellite capable of being containedin a restricted area and of being expanded in outer space by centrifugalforce.

Generally speaking, the foregoing objects as well as others areaccomplished in accordance with this invention by providing a circularlyfolded packaging arrangement for a flexible sheet which can be readilyopened in outer space by the centrifugal force imparted to the packagedsatellite by rotation of the carrier vehicle.

A more complete understanding of the invention and many of the attendantadvantages thereof will be readily appreciated as the same becomesbetter understood by reference to the following detailed descriptionwhen con sidere connection with the accompanying drawings wherein:

FIG. 1 is a top view of the expanded reflector satellite;

FlG. 2 is a perspective view of the folded reflector satellite;

FIG. 3 is a cross sectional somewhat schematic view taken line 33 ofFlG. 2; and,

FIG. 4 is a side View of the folded reflector satellite in a carriervehicle to be carried into outer space.

Referring now to the drawings wherein like reference numerals designateidentical or corresponding parts throughout the several views, and moreparticularly to PEG. 1 whercon the satellite, generally indicated by the'icc reference numeral 11, is shown as being formed of a circula, thin,planar sheet 12. The sheet is preferably composed of flexible,lightweight aluminum coated plastics material, such for example asMylar, having a thickness of approximately one mil to two mils, however,any similar flexible and tear resistant material capable of reflectinglight and other electromagnetic waves may be used. An aperture 13 may becentrally formed in the circular sheet during the folding operation bythe folding ma chine disclosed in applicants copending patentapplication, Serial Number 8,203, filed February 11, 1960, now PatentNumber 3,010,372.

As more clearly shown in FIG. 2, the reflector 11, in a packagedcondition, is provided with a center substantially planar disc portion14 which gradually develops into radial folds, or pleats, 15 extendingto the periphery thereof, thereby forming saw-tooth folds thereon.Pleats 3.5 are shown as becoming progressively larger in height, oramplitude, toward the outermost edge of the reflector satellite ii. Thesaw-tooth edges 21 are preferably of 111 'form height and evenlydistributed around the periphery. As shown somewhat schematically inFIG. 3, the and lower portions of pleats 15 are identical in amplitudeincreasing progressively towards the outer edge thereof. The satelliteis therefore shown to be substantially symmetrical about the center axiswhen in a packaged condition.

The packaged configuration may be launched into the upper earthsatmosphere in a container 16 positioned in a nose cone 1? of amultistage rocket, as shown on FIG. 4, or from one of the later stagesof the space probe. A sprin 13 can be utilized to eject the packagedconfiguration from the posterior end of the nose cone upon separationthercof from the rocket motor 119.

The spin of the carrier is adequate of itself to open and expand thepackaged satellite when ejected, thereby aking the use of inflationmeans unnecessary and effecting a s; ing in payload. A space probe orcarrier vehicle is necessarily spin stabilized and is therefore spin- 1n about its longitudinal axis as the packaged configuration is ejectedinto outer space. The spin of the carrier vehicle is imparted to theejected packaged configuration whereupon the folded configuration isfully opened by cen rifugal force subsequent to the ejection thereof byresilient means 18. After opening, the configuration rem ins in theextended position due to the absence of atmosphere in the outer spaceregions.

The packaged configuration is very desirable in that a large sizedcircular planar satellite may be folded into a small compact packagedconfiguration which may be placed in a reasonably small cavity 22 in anose cone 17. Moreover, although of a relatively large size, thesatellite is extremely lightweight.

Obviously numerous modifications and variations of the present inventionare possible in the light of the above teachings. It is therefore to beunderstood that within of the appended claims the invention may bepracticed otherwise than as specifically described.

' rat is claimed as new and desired to be secured by Letters latent ofthe United States is:

l. A reflector space satellite capable of being compactly stored in afolded condition within a nose cone cavity of a carrier "ehicle andbeing readily unfurled to an extended position at a predeterminedaltitude by centrifugal force, comprising:

a thin flexible plastics sheet of material having a reflective surfacethereon;

said flexible plastics sheet when in the folded compactly storedposition having (a) a centrally located substantially planar discportion,

References in the file of this patent UNl'EED STATES PATENTS MorganSept. 12, Bruun Oct. 15, Dcerr Feb. 6, Bauer Aug. 14-, Fitzgerald et a1Sept. 11, Robins et a1. Dec. 10, Gregory Apr. 7, Huso June 28, Canfieldet a1. Jan. 10, OSullivan Aug. 15, Lanford Nov. 28,

1. A REFLECTOR SPACE SATELLITE CAPABLE OF BEING COMPACTLY STORED IN AFOLDED CONDITION WITHIN A NOSE CONE CAVITY OF A CARRIER VEHICLE ANDBEING READILY UNFURLED TO AN EXTENDED POSITION AT A PREDETERMINEDALTITUDE BY CENTRIFUGAL FORCE, COMPRISING: A THIN FLEXIBLE PLASTICSSHEET OF MATERIAL HAVING A REFLECTIVE SURFACE THEREON; SAID FLEXIBLEPLASTICS SHEET WHEN IN THE FOLDED COMPACTLY STORED POSITION HAVING (A) ACENTRALLY LOCATED SUBSTANTIALLY PLANAR DISC PORTION, (B) A SERIES OFRADIAL PLEATS RADIATING OUTWARDLY FROM SAID CENTRALLY LOCATED DISCPORTION, (C) SAID PLEATS BEING SPIRALLY WRAPPED AROUND SAID DISCPORTION, (D) THE AMPLITUDE OF SAID PLEATS PROGRESSIVELY INCREASING FROMSAID DISC PORTION TO THE OUTER PERIPHERY OF SAID FLEXIBLE SHEET, SAIDFLEXIBLE SHEET UPON BEING EXTENDED BY CENTRIFUGAL FORCE AT THEPREDETERMINED ALTITUDE BEING READILY UNFURLED TO ASSUME AN ESSENTIALLYOVERALL DISC CONFIGURATION.